Air Source Vs. Ground Source Input

[nobody05]

Well the time has come for me to build a new place with all the decisions being made 1 big one sticks out! Is it worth going ground source? My hvac guy is pushing for (cant imagine why for the extra $ lol) But cant seem to cruch the numbers over a 95% w/ 18 seer air-to-air heat pump! Any input/opions about such a system would be much appreciated! Thanks

[UMDSportsman]

Summer of 2009 bought a house and had to replace furnace and heat pump. I would have went with ground source, but I did not have the cash to put in the ground source, and i did not like the idea of another loan to pay off. Once it gets around about 25 deg F, it is somewhat useless, it blows air that is not that warm, maybe mid 60's, where the furnace i think is in the 80's. I have the thermostat set to run the heat pump if temp >15 or 20, and if it has to warm up the house less than 2 deg; if outside temp >40 deg, heat pump only, if between 15/20 and 40 deg furnace and heat pump, if less than 15/20 furnace only. I also have a houlse built in the 70's thats not that well insulated, and has poorly designed/installed duct work. With new construction, i would hope you would be in a lot better shape than I am. I have a 95%, and i think a 16 SEER.

[fishwidow]

I have a gound source heat pump. It was installed mid August, so I don't have a lot of history related to efficiency for heating. This was a retrofit, and under normal circumstances I would not be able to justify the cost, but with tax credits, energy rebates from the state and utility company, the cost was brought down to something pretty manageable--only slightly more than what a high efficiency A/C would have cost. Those programs have expired; I was lucky to have good timing.

If I were building a new house, I would seriously consider the ground source heat pump. It can be used to preheat water and can also be used for in-floor heating.

Again, I haven't had enough heating experience with it yet to give actual hard facts on its efficiency, but I have to believe running a pump and condensor is cheaper than fossil fuel burning, especially if those costs are expected to rise. The quality of the heat is fine and the quality of the cooling is great. I should mention that we also heat with an efficient wood stove. I considered replacing an oil burner with a ground source heat pump at our lake place, but could not justify the cost and went with propane and an electric plenum heater which gives us a dual fuel rate offered by the power company, but if I were building I would probably do the heat pump.

Good Luck with your decision.

[beer batter]

I'm in the same boat, looking at building a new place and was seriously looking in to geothermal. Kept hearing that you'll never make your money back as fast as what all the articles state you will, and that is because of the heat pump's continual need for replacement. Apparently the average lifespan of a heat pump is 7 years. The replacement cost is roughly $1000. There goes a lot of energy savings every 7 years.

[nobody05]

Yeah I was talking to a guy that's got a newer era rambler home approx early 80's approx 2400 sq ft. He claims he can heat and cool his house for under $500 god forbid the house is spray foamed insulated to the max with a %95 w/18 seer heat pump. The numbers just dont mesh. Sure they say a 1$ a day but even at $365 a year compared to $500 you would never come out in your lifetime to justify the 25K to install!

[DrKen]

I had to make the same decision a couple of years ago. I had to replace a 30 year old HVAC system. I maintain a mall with 7 ground source heat pumps so I am more than a little familiar with them. When I ran the numbers I went with a air source heat pump for my home. I didn't feel I could make up the infrastructure costs in the time i would be in my home and there is not(at that time) any resale increase due to the geothermal being in the home. I also have control box that allows me to set the temp that the air source kicks on and i use it down to about 20 degrees. At temps below 45 do not expect it to replace your furnace but it does assist. As far as life span to the geo's they originally were 7 years but the new ones come with 10 year warranties and you could reasonably expect a 20 year lifespan or more. All the major brands use Copeland compressors and remember all they really are is a air conditioner that reverses and they should last as long as one of them. You just have to run the numbers and make your own decisions. If I was building new, I would seriously look at geo but air source are constantly getting better. There is at least 1 air source that says it will work in all weather(hallowell?) Hope this helps.

[Barony]

Check the rate you get from the company that provides your electricity. We discovered after the fact that we were not going to get off peak, so instead of paying .03 like my rural friends are w/ the ground unit, we are paying .11 1/2. Sure do like the unit though.

[Chad711]

As usual there is alot of confusion with heat pump systems.

Air source hps are great, and what heat they do produce at 20 degrees is still cheaper than most sources of heat. at 20 degrees outdoor air a properly sized/installed (RARE) hp will provide about a 15-20 degree rise in air temp, whereas a fossil fuel (lp, propane etc) will give on avg a 45 degree rise.

There is another option not talked about much and that is ETS systems (Electric thermal storage systems).

Steffes (Dickenson, Nd) makes ETS systems that range from a small room unit to complete forced air system, and when combined with a hp these are VERY close to the same operational costs as Geo, with a lower initial install cost. If you have a dealer in your area call them and ask for more info.